The geostrophic velocity field in shallow water over topography

A recent note (Hopkins, T.S., 1996. A note on the geostrophic velocity field referenced to a point. Continental Shelf Research 16, 1621–1630) suggests a method for evaluating absolute pressure gradients in stratified water over topography. We demonstrate that this method requires no along-slope bottom velocity, in contradiction to what is usually observed, and that mass is not conserved.